struct ListNode* detcetCycle(struct ListNode* head)
{
	struct ListNode* slow, * fast;
	slow = fast = head;
	while (fast && fast->next)
	{
		slow = slow->next;
		fast = fast->next->next;
	
		if(meet=fast)
		{ 
	strcut ListNode* meet = slow;
	while (meet != head)
	{
		meet = meet->next;
		head = head->next;
	}
	return meet;



}
	}
	return NULL;
}